Condition adaptive-type control method for internal combustion engines

ABSTRACT

To perform the proper control conforming to the intent of a driver of an automotive vehicle under any condition which is encountered by the vehicle, optimum control methods are preliminarily classified in accordance with categories relating to conditions of the vehicle and categories relating to intents of the driver and the classified optimum control methods are stored in a memory, thereby selecting one of the control methods corresponding to the combination of the categories to which the vehicle condition and the driver&#39;s intent detected during the running of the vehicle belong.

BACKGROUND OF THE INVENTION

The present invention relates to a method for controlling a fuelinjection system and an ignition system in an internal combustionengine, and more particularly to a control method for the internalcombustion engine of an automotive vehicle which is well suited to meetthe driver's various requirements relating to the driving of thevehicle.

Heretofore known electronic fuel injection control systems employ amethod of intermittently supplying the fuel in an amount correspondingto the intake air flow rate and also varying the fuel quantity duringthe period of acceleration and deceleration (refer the below-mentioned(1) and (2)). During constant speed driving, this method can supply theengine with an amount of air and a fuel quantity which are proportionalto the load and therefore there is no inconvenience. However, the methodis disadvantageous in that the engine cannot be controlled properlyduring transient conditions, e.g., times of acceleration anddeceleration.

As described above, the conventional control systems have been unable toprovide satisfactory functions to meet the highly sophisticated anddiversified requirements relating to driving performance. On the otherhand, while torque servo controls and speed servo controls are proposed(e.g., the below-mentioned techniques (3) and (5)) to meet sophisticatedrequirements, no satisfactory consideration has been given to an overallcontrol ensuring proper control under all conditions which areencountered by the vehicle.

Note that the prior art techniques relating to these types of systemsinclude the following, for example.

(1) IDEI: “The Engine Controls”, Institute of Electrical Engineers ofJapan Journal Vol. 101, No. 12, P. 1148 (December 1981) . . . Controlsby Microcomputers; This relates to table look-up systems.

(2) NAGAYAMA et al: Centralized Control of Engine by Microcomputers,Systems and Controls, Vol. 24, No. 5, P. 306 (May 1980); This relates toflow charts of engine operations, fuel injection control, ignitiontiming control and idling speed control.

(3) T. TABE et al: On the Application of Modern Control Theory toAutomotive Engine Control, IECOM '85; This relates to torque servos.

(4) JP-A-57-73836

(5) ITO: “Fuel Economy Optimalizing Control System with Compound ControlAction on Engine and Transmission”, Automotive Engineering, February 83;This relates to speed servos.

The above-mentioned conventional techniques have failed to give dueconsideration in comprehensively grasping as a system the control of theengine on a vehicle. Thus, there have been a lack of engine controlmethods which could meet all the situations in which the vehicle is tobe used and the difficulty to establish the necessary parameters forsuch engine control methods has been a disadvantage.

One reason is that the conventional engine control methods are made upof static models despite the fact that the conditions which areencountered by a vehicle are a repetition of steady-state operations,e.g., the constant speed running and idling operation and the transientstate operation such as acceleration and deceleration. Moreover, therequirements for the behaviour of the vehicle during the transientconditions have become increasingly severe on the part of the users ofthe vehicles. As a result, even if measuring devices are installed toobserve the transient conditions, their full utilization cannot beensured by the static model.

In the case of the conventional methods in which the static controlmodel is compensated for the transient conditions, a great deal ofmanhours are required to materialize and adjust an engine control methodfor each of different types of vehicles which are diversely different invehicle characteristics, measuring devices, actuators, etc.

SUMMARY OF THE INVENTION

With a view to overcoming the foregoing deficiencies in the prior art,it is an object of the invention to provide a method of controlling aninternal combustion engine mounted on a vehicle in which differentvehicle conditions and driver's different intents are respectivelydiscriminated and divided into categories so as to select a proper oneof a plurality of engine control methods corresponding to each ofvarious combinations of the categories.

To adapt the dynamic characteristic of the vehicle to the sensitivity orfancy of the driver, it is only necessary to discriminate and classifythe preferences of the driver into certain preference modes, such as,sporty, luxury and economy modes of driving and change the parameters ofthe respective control methods to suit the corresponding modes. Torealize the selection of the engine control methods corresponding to theabove discrimination and classification, it is only necessary to developthe software of the computer incorporated in the engine control systemin such a manner that a higher priority level is allocated to allowexecution of the condition discriminating and classifying function inpreference to the other functions.

The discrimination and classification of the vehicle's conditions anddriver's intents are performed in the following way. The conditions ofthe vehicle can be detected in terms of the vehicle speeds and vehiclespeed changes. The driver indicates an intent concerning the driving byengaging the torque transmission mechanism (the clutch and thetransmission) and depressing the brake pedal or the accelerator pedal.In other words, the driver indicates his intent in correspondence to thesituation of the vehicle by selectively depressing the two pedals. Theintent is represented by the angles and angular velocities of the pedalsand their time series loci. The conditions of the vehicle and theintents of the driver can be detected in detail in accordance with themeasured values from a certain prior time up to the present time as tothe vehicle speed and its time rate of change and the angle and angularvelocity of the brake and accelerator pedals. The angular velocity ofthe accelerator pedal is equivalent to the acceleration rate {dot over(θ)}ac in FIG. 4. In addition, by utilizing these measured values, it ispossible to estimate the condition of the vehicle and the intent of thedriver and predict the future condition of the vehicle.

As regards the construction of the running controls of the vehicle, aswill be described later with reference to the illustrated embodiments,there are a method of realizing the controls by a cascade connection oftorque servo system, speed servo system and tracking servo system andanother method of preparing the previously mentioned various enginecontrol methods in a parallel manner.

The method of determining the preferences of the driver for vehicleoperation may, for example, be to provide three selector switchesrespectively corresponding to the “sporty”, mode placing emphasis ondrivability, “luxury” mode placing emphasis on driving comfortabilityand “economy” mode placing emphasis on practicality so that theparameters of each engine control method are changed in response to theselection of one of the selector switches.

The computer used for realizing the abovementioned method may be of thehigh type speed and the operation program may be prepared such that thecondition discrimination and the selection of the engine control methodsare effected most preferentially.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an embodiment of the invention.

FIG. 2 is a block diagram showing another embodiment of the invention.

FIG. 3 is a block diagram showing an exemplary construction of thecomputer program used in the embodiment of FIG. 1.

FIG. 4 is a diagram showing the relation between the vehicle conditionsand the driver's intent and the respective engine control methods.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The principle of the present invention will now be described first withreference to FIG. 4.

FIG. 4 shows the discrimination and classification of the vehicleconditions and driver's intent and engine control methods correspondingto the respective categories.

The vehicle conditions are roughly divided into a rest condition (V=0)and a running condition (V>0). The driver's intent is discriminated onthe basis of six different conditions including the operation state ofthe torque transmission mechanism (clutch) the depression of the brakepedal (breaking, θbr>0), non-depression of the brake pedal (θbr=0) andthe accelerator pedal (coasting, θac=0) the depression of theaccelerator pedal (acceleration, the θac≧θaca) the depressed acceleratorpedal (steady running, θacd<θac<θaca) at rest steady running, {dot over(θ)}acd<{dot over (θ)}ac<{dot over (θ)}aca) and the restored acceleratorpedal (deceleration, {dot over (θ)}ac≦{dot over (θ)}acd).

When the torque transmission mechanism is on (engaged) and theaccelerator pedal is depressed, a control for the accelerationrequirement is performed ( in FIG. 4). With the vehicle running, whenthe accelerator pedal is released and the brake pedal is depressed, adeceleration control is performed ( in FIG. 4). At this time, if theidle switch is on (which indicates that the acceleration pedal isreleased) and the engine speed is excessively high, a fuel cut-offcontrol is performed ( in FIG. 4).

In the running condition, if the vehicle is neither accelerated nordecelerated, an air-fuel ratio control is performed to maintain theair-fuel ratio at a desired value ( in FIG. 4).

When the torque transmission mechanism is off, an idle speed controlcomes into action to control the engine speed to maintain it at adesired value ( in FIG. 4). At this time, if the accelerator pedal isdepressed, the switching to the previously mentioned air-fuel ratiocontrol is effected despite the fact that the engine is racing.

The method of discriminating and classifying the conditions of thevehicle and the intents of the driver to select the proper enginecontrol method is well suited to progressively deal with the diverserequirements of the user of the vehicle and the introduction of newtechniques which meet the requirements. To the design and developmentengineer as well as persons who attend matching of the engine controlmethods with the actual vehicle (the adjustment of the parameters), thismeans advantages that it is necessary to understand only the enginecontrol methods corresponding to the required categories, that amodification of the computer program requires only the modification ofsome modules and so on.

An embodiment of the invention will now be described with reference toFIG. 1. The block diagram of FIG. 1 comprises a condition discriminatingunit and cascaded control systems operable in response to the outputs ofthe former.

The conditions discriminating unit 1 detects the conditions of a vehiclein terms of a vehicle speed v, engine speed N, engine output torque Tand a distance L between the vehicle and an obstacle ahead or thepreceding vehicle and it also detects the intent of the driver inaccordance with the changes in time (dynamic changes) obtained byoperating on a signal 20 indicative of the brake pedal angle θ_(br), asignal 19 indicative of the accelerator pedal angle θ_(ac) and theirpast values. In accordance with these detection results and thepreference of the driver, a determination is made as to which of theengine control methods is required and the decision of the constructionof the cascade-connected running control systems, the selection ofparameters and the modification of their values are performed.

The running control systems include the torque servo system, speed servosystem and tracking servo system which are cascaded from the inner sidenear to an engine 2 so as to control its speed N and torque T.

The supply of fuel to the engine 2 is effected by a fuel injectioncontrol system 3 and the ignition timing is controlled by an ignitiontiming control system 4.

A torque control mechanism 5 determines fuel quantity and ignitiontiming corresponding to a torque deviation required by the controlsystems and the results are applied to the fuel injection control system3 and the ignition timing control system 4. While the ignition timingcontrol system 4 operates in accordance with the ignition timingdetermined by the torque control mechanism 5 at the low speed operationand the constant speed driving, during the transient period the ignitiontiming can be controlled directly if the condition discriminating unit 1requires a rapid surge preventive measure.

When the torque servo system is selected by the condition discriminatingunit 1, its reference value is applied to a torque reference setup unit6 from the condition discriminating unit 1. Thus, the input to thetorque control mechanism 5 represents the difference value between thetorque reference value and the measured value of the engine torque. Atorque servo system selector switch 7 is selected in accordance with theresult of the decision in the condition discriminating unit 1. A torquemeasuring device 8 performs the operation of engineering valueconversion and smoothing on the measured value of the torque. Where theupstream speed servo system is selected, the input to the torque controlmechanism 5 is the output of a speed control mechanism 9.

Where the driving involves a frequent repetition of acceleration anddeceleration, the driver demands an increase in the torque by depressingthe accelerator pedal and commands a decrease in the torque by releasingthe depression. Thus, the condition discriminating unit 1 applies atorque desired value corresponding to the movement of the acceleratorpedal and engine speed. Alternatively, a torque deviation may bedirectly applied to the torque controlling mechanism 5.

When the condition discriminating unit 1 selects the idle speed control(ISC) or the driver selects the constant speed driving (cruising)control, the condition discriminating unit 1 selects a selector switch10 so that the vehicle speed reference value applied to a speedreference setup unit 11 from the condition discriminating unit 1 iscompared with the actual measured vehicle sped and the speed controllingmechanism 9 controls the vehicle speed to approach the reference value.The actual vehicle speed is measured by a vehicle speed measuring device13 in which the axle speed derived from the engine 2 through a gear 12is corrected for variation in the tire diameter, etc., and the resultingtime series data is smoothed out.

Even if the cruise control has been selected, when the driver depressesthe accelerator pedal, the switch 7 is turned on and the switching tothe torque servo system is effected.

Where the vehicle is provided with a sensor for measuring the distancefrom an obstalcle obstacle ahead, a signal 17 from a cruising speedselector switch (not shown)17is selected so that when the distance fromthe preceding vehicle is less than an allowable value, the switching ismade from the speed servo system to the tracking servo system.

A tracking control mechanism 14 determines an increase or decrease inthe vehicle speed in accordance with the difference between the measuredvalue from a distance sensor 15 for measuring the distance from anobstacle ahead and the predetermined following distance reference valuecorresponding to the vehicle speed and the result is applied to thespeed control mechanism 9. The following distance reference value isdetermined by the condition discriminating unit 1 and sent to afollowing distance reference setup unit 16. This value is utilized forthe calculation of a distance difference.

The following Table 1 shows the correspondence between the enginecontrol methods to be selected by the condition discriminating unit 1and the construction of the cascade control system.

TABLE 1 Construction ENGINE Torque Speed Tracking CONTROL Servo ServoServo METHODS System System System Acceleration Control ∘ Δ ΔDeceleration Control ∘ Δ Δ Fuel Cut-Off Control ∘ — — Air-Fuel Ratio ∘ ∘∘ Control Idle Speed Control — ∘ — Explanation ∘ Great contribution ΔModerate contribution — Small contribution

When the results of the condition discrimination indicates that theacceleration or deceleration control is needed, the torque servo systemfunctions principally. At this time, the speed servo system alsofunctions if the constant speed driving is being selected and also thetracking servo system functions if the distance sensor is in operation.The fuel cut-off control is performed within the range of the torqueservo system. The air-fuel ratio control is performed during the torqueservo system for the purpose of improving the fuel consumption andreducing the exhaust gas emission. The air-fuel ratio control functionseffectively even during the constant speed driving as well as thetracking driving. In the case of the idle speed control, the speed servosystem having the idle speed as the reference value functions.

The following Table 2 shows the results of the preference mode selectionor input signals 18 to the condition discriminating unit 1.

TABLE 2 Control System Construction Torque Speed Tracking PreferenceServo Servo Servo Node System System System Sporty ∘ — — Luxury ∘ ∘ ∘Economy ∘ Δ — ∘ Great contribution Δ Moderate contribution — Smallcontribution

As will be seen from Table 2, each of the sporty, luxury and economymodes corresponds mainly through changing of the control parameters ofthe torque servo system. As regards the “luxury” mode, coupled with theprovision of the cruise control function and the distance sensor, thespeed servo system and the tracking servo system function effectively.

In the case of the “economy” mode, while the speed servo system may beused jointly, a control algorithm is used which ensures saving of thefuel consumption even if the degree of the cruise control is reduced.

FIG. 2 shows another embodiment of the invention which has the samepurposes as the embodiment of FIG. 1. FIG. 2 shows a construction inwhich the proper engine control method is selected from alternatives forthe engine control methods in accordance with the discrimination resultof the condition discriminating unit 1. The alternatives of the enginecontrol methods include basically an acceleration control 21,deceleration control 22, fuel cut-off control 23, air-fuel ratio control24 and idle speed control 25. Each of these five engine control methodsis responsive to the results of calculations to supply a fuel quantityand an ignition timing to a fuel injection control system 3 and anignition timing control system 4, respectively.

Where the acceleration control, the deceleration control or the fuelcut-off control is selected, rapid application of the control may havethe danger of causing a surging phenomenon depending on the condition ofthe vehicle and therefore a predictive calculation is made on the basisof the vehicle condition and the selected control method. If theoccurrence of a surging phenomenon is predicted, the air fuel-ratiocontrol is selected or alternatively the parameter values of the alreadyselected engine control method are changed.

The computer is essential for materializing the overall control relatingto the engine as shown in FIG. 1. FIG. 3 shows the construction of thecomputer program.

The program shown in FIG. 3 is started at an interrupt step 31 and thenat an interrupt decision step 32 a branching is made to a periodicinterrupt step 33 or an end of A/D conversion interrupt step 35 whichtakes place after an A/D conversion start step 34 initiated by theinterrupt step 33. After the end of A/D conversion interrupt step 35,the condition discrimination described in connection with FIG. 1 isperformed and the proper engine control method is selected. Inaccordance with the selection result, a task distributing step 36 callsany of the following tasks. Assigned to a task level 0 are the ignitiontiming control 4, the fuel injection control 3 and the torque control 5for rapid response purposes. Assigned to a task level 1 are the speedcontrol 9, the tracking control 14, etc. Assigned to a task level 2, etseq., are the other programs which are allowed to respond more slowly.

From the present program construction point of view, there is a featurethat when the vehicle condition and the driver's intent are subjected toA/D conversion and inputted, a condition discriminating step isperformed thereby rapidly responding to the transient condition.

In accordance with the present invention, by virtue of the fact that thecondition of a vehicle and the driver's intent can be detected rapidlyfrom moment to moment and moreover the proper engine control method tobe used in response to the detection results can be determinedaccurately, there is the effect of improving the driving performance,ensuring effective utilization of the engine performance, and rapidlydeveloping engine control methods matched to different engineperformances of different vehicles with the improved productivity ofsoftware therefor.

What is claimed is:
 1. A condition adaptive-type control method for aninternal combustion engine mounted on an automotive vehicle having atorque transmission mechanism, a brake pedal and an accelerator pedal,comprising the steps of: categorizing driver's intents and vehicleconditions, respectively, into a plurality of categories, and preparingdifferent engine control methods for different combinations of saidcategories; detecting a driver's intent in accordance with the state ofengagement or disengagement of said torque transmission mechanism, theangle of said brake pedal and the angle of said accelerator pedal;detecting said vehicle condition from the speed of said vehicle; andselecting one of said engine control methods in accordance with acombination of the categories to which said detected driver's intent andvehicle condition belong.
 2. A method according to claim 1, wherein saidengine control methods differ by the fact that they refer to differentparameter values.
 3. A method according to claim 2, wherein saidparameter values may be changed according to a driver's preference.
 4. Amethod according to claim 1, wherein said detecting step is performedwith a higher priority than other steps.
 5. A method according to claim1, wherein said selecting step further includes a step of anticipatingthe occurrence of a future phenomenon which is predicted to occur at atime when a selected control method is employed so as to select oneengine control method in accordance with a result of said anticipating.6. A condition adaptive-type control method for an internal combustionengine mounted on an automotive vehicle, comprising the steps of:categorizing driver's intents and vehicle conditions into six categoriesand two categories, respectively, and preparing five types of enginecontrol methods, including an acceleration control method, adeceleration control method, a fuel cut-off control method, an air/fuelratio control method and an idle speed control method, which correspondto respective combinations of said categories; detecting one of said sixtypes of driver's intents including engaging or disengaging of a torquetransmission mechanism, braking, transition or coasting, deceleration,running and acceleration; detecting said vehicle condition includingengine speed to determine whether said vehicle is in a rest condition ora running condition; and selecting one of said six types of enginecontrol methods in accordance with said combination of categories towhich said detected intent and vehicle condition belong.
 7. A conditionadaptive-type control system for an internal combustion engine mountedon an automotive vehicle, comprising: a torque servo system includingfirst reference setup means for setting up a first reference signal ofan engine torque, torque measuring means measuring the actual torque ofsaid engine, first comparing means for comparing said first referencesignal with said measured torque so as to produce a first error signalindicative of a difference between said reference signal and saidmeasured torque, and torque control means for producing a torque controlsignal in accordance with said first error signal; a speed servo systemincluding second reference setup means for setting up a second referencesignal of a vehicle speed, vehicle speed measuring means for measuringan actual vehicle speed of said vehicle, second comparing means forcomparing said second reference signal with said measured vehicle speedso as to produce a second error signal indicative of a differencebetween said second reference signal and said measured vehicle speed,and speed control means for producing a speed control signal inaccordance with said second error signal; said speed servo systemincluding said torque servo system as a minor servo loop for said speedservo system; a tracking servo system including third reference setupmeans for setting up a third reference signal of a distance to a forwardvehicle, distance measuring means for measuring the actual distance to aforward vehicle, third comparing means for comparing said thirdreference signal with said measured distance so as to produce a thirderror signal indicative of a difference between said third referencesignal and said measured distance, and tracking control means forproducing a tracking control signal in accordance with said third errorsignal; said tracking servo system including said speed servo system asa minor servo loop for said tracking servo system; means for sensing anaccelerator pedal angle; means for sensing a brake pedal angle; meansfor sensing engine speed; means for detecting whether a torquetransmission mechanism of said vehicle is engaged or disengaged; arunning control selector switch for selecting one of said servo systems;condition discriminating means responsive to the outputs of saidaccelerator pedal angle sensing means, brake pedal angle sensing means,engine speed sensing means, torque transmission mechanism detectingmeans and said selector switch for categorizing a driver's intent and avehicle condition in accordance with said outputs, for determining oneengine control method among different engine control methods previouslystored in said condition discriminating unit in accordance with acombination of said categories of said driver's intent and said vehiclecondition, and for determining one servo system among said trackingservo system, speed servo system and said torque servo system inaccordance with said output of said running control selector switch andsaid first, second and third reference signals so as to control saidselected servo system to operate in accordance with said determinedengine control method and to provide said reference signals to saidreference setup units of the selected servo system; and engine controlmeans for controlling fuel injection and ignition timing of said enginein response to said torque control signal from said torque servo system.8. A condition adaptive-type control system according to claim 7,wherein said different engine control methods include an accelerationcontrol method, a deceleration control method, a fuel cut-off method, anair/fuel ratio control method and an idle control method, said idlecontrol method being operated with said speed servo system and the otherfour engine control methods being operated with said torque servosystem.
 9. A condition adaptive-type control method for an internalcombustion engine mounted on an automotive vehicle having a torquetransmission mechanism, a brake pedal and an accelerator pedal,comprising the steps of: providing a plurality of different enginecontrol methods for said engine, each of said different engine controlmethods including parameters and being associated with a combination ofone of a plurality of vehicle conditions and one of a plurality ofdriver's intents; discriminating said driver's intent by detecting thestate of engagement or disengagement of said torque transmissionmechanism, and by sensing the angle of said brake pedal and the angle ofsaid accelerator pedal; discriminating said vehicle condition by sensingthe speed of said vehicle and determining whether said vehicle is in arest condition or not; and selecting one of said engine control methodsin accordance with a combination of the discriminated driver's intentand vehicle condition.
 10. A method according to claim 9, wherein saidstep of discriminating said driver's intent further includes calculationof an acceleration rate of said vehicle on the basis of the sensed angleof said accelerator pedal.
 11. A method according to claim 10, whereinsaid plurality of engine control methods include an acceleration controlmethod, a deceleration control method, a fuel cut-off control method, anair-fuel ratio control method and an idle speed control method, and saidstep of selecting one of said engine control methods is executed byselectively choosing one of the following steps: (1) selecting theacceleration control method when said torque transmission mechanism isengaged and said acceleration rate {dot over (θ)}ac is greater than afirst reference value {dot over (θ)}aca; (2) selecting the decelerationcontrol method when said torque transmission mechanism is engaged, thevehicle speed is greater than zero and either said acceleration rate{dot over (θ)}ac is equal to or smaller than a second reference value{dot over (θ)}acd or said acceleration pedal is released; (3) selectingthe fuel cut-off control method when said torque transmission mechanismis engaged, said acceleration pedal is released, and said engine speedis greater than a reference value; (4) selecting the air-fuel ratiocontrol method either when said torque transmission mechanism isengaged, said vehicle speed is greater than zero and said accelerationrate {dot over (θ)}ac is between the first and second reference valuesof {dot over (θ)}aca and {dot over (θ)}acd, or when said torquetransmission mechanism is disengaged and said acceleration pedal isdepressed; and (5) selecting the idle speed control method when saidtorque transmission mechanism is disengaged and said acceleration pedalis released.
 12. A method according to claim 9, wherein each of saidengine control methods further includes a step of updating values ofsaid parameters in accordance with each combination of the enginecondition and the driver's intent.
 13. A condition adaptive-type controlmethod for an internal combustion engine mounted on an automotivevehicle having a torque transmission mechanism, a brake pedal and anaccelerator pedal, comprising the steps of: programming a plurality ofdifferent engine control methods with parameters for said engine, eachof said different engine control methods being associated with acombination of one of a plurality of vehicle conditions and one of aplurality of driver's intents, including braking, coasting, transientoperation, decelerating, cruising and accelerating; discriminating thedriver's intent by detecting the state of engagement or disengagement ofsaid torque transmission mechanism, the angle of said brake pedal andthe angle of said accelerator pedal; discriminating said vehiclecondition by detecting engine speed and determining whether said vehicleis in a rest condition or not; and selecting one of said engine controlmethods in accordance with a combination of the discriminated driver'sintent and vehicle condition.
 14. A condition adaptive-type controlsystem for an internal combustion engine mounted on an automotivevehicle having a torque transmission mechanism, a brake pedal and anaccelerator pedal, comprising: means for categorizing driver's intentsand vehicle conditions, respectively, into a plurality of categories,and for preparing different engine control methods for differentcombinations of said categories; means for detecting a driver's intentin accordance with the state of said torque transmission mechanism, theangle of said brake pedal and the angle of said accelerator pedal; meansfor detecting said vehicle condition from the speed of said vehicle; andmeans for selecting one of said engine control methods in accordancewith a combination of the categories to which said detected driver'sintent and vehicle condition belong.
 15. A condition adaptive-typecontrol system according to claim 14, further includes means fordifferentiating said engine control methods in a manner that they referto different parameter values.
 16. A condition adaptive-type controlsystem according to claim 15, further includes means for changing saidparameter values according to a driver's preference.
 17. A conditionadaptive-type control system according to claim 14, further includesmeans for performing detecting operations of both said detecting meansprior to other means.
 18. A condition adaptive-type control systemaccording to claim 14, further includes means for anticipating theoccurrence of a future phenomenon which is predicted to occur at a timewhen a selected control method is employed so as to select one enginecontrol method in accordance with a result of said anticipating.
 19. Acondition adaptive-type control system for an internal combustion enginemounted on an automotive vehicle comprising: means for categorizingdriver's intents and vehicle conditions into six categories and twocategories, respectively, and for preparing five types of engine controlmethods, including an acceleration control method, a decelerationcontrol method, a fuel cut-off control method, an air/fuel ratio controlmethod and and idle speed control method, which correspond to respectivecombinations of said categories; means for detecting one of said sixtypes of driver's intents including a torque transmission mechanism,braking, transition or coasting, deceleration, running and acceleration;means for detecting said vehicle condition including engine spew todetermine whether said vehicle is in a rest condition or a runningcondition; and means for selecting one of said five types of enginecontrol methods in accordance with said combination of categories towhich said detected intent and vehicle condition belong.
 20. A conditionadaptive-type control system for an internal combustion engine mountedon an automotive vehicle having a torque transmission mechanism, a brakepedal and an accelerator pedal, comprising: means for providing aplurality of engine control methods for said engine, each of saiddifferent engine control methods including parameters and beingassociated with a combination of one of a plurality of vehicleconditions and one of a plurality of driver's intents; means fordiscriminating said driver's intent by detecting the state of saidtorque transmission mechanism, and by sensing the angle of said brakepedal and the angle of said accelerator pedal; means for discriminatingsaid vehicle condition by sensing the speed of said vehicle and fordetermining whether said vehicle is in a rest condition or not; andmeans for selecting one of said engine control methods in accordancewith a combination of the discriminated driver's intent and vehiclecondition.
 21. A condition adaptive-type control system according toclaim 20, wherein said means for discriminating said driver's intentincludes means for calculating an acceleration rate of said vehicle onthe basis of the sensed angle of said acceleration pedal.
 22. Acondition adaptive-type control system according to claim 21, whereinsaid plurality of engine control methods include an acceleration controlmethod, a deceleration control method, a fuel cut-off control method, anair-fuel ratio control method and an idle speed control method, and saidselecting means includes: means for selecting the acceleration controlmethod when said torque transmission mechanism is engaged and saidacceleration rate θac is greater than a first reference value θaca;means for selecting the deceleration control method when said torquetransmission mechanism is engaged, the vehicle speed is greater thanzero and either said acceleration rate θac is equal to or smaller than asecond reference value θacd or said acceleration pedal is released;means for selecting the fuel cut-off control method when said torquetransmission mechanism is engaged, said acceleration pedal is released,and said engine speed is greater than a reference value; means forselecting the air-fuel ratio control method either when said torquetransmission mechanism is engaged, said vehicle speed is greater thanzero and said acceleration rate θac is between the first and secondreference values of θaca and θacd, or when said torque transmissionmechanism is disengaged and said acceleration pedal is depressed; andmeans for selecting the idle speed control method when said torquetransmission mechanism is disengaged and said acceleration pedal isreleased.
 23. A condition adaptive-type control system according toclaim 20, further includes means for updating values of said parametersin each of said engine control methods in accordance with eachcombination of the engine condition and the driver's intent.
 24. Acondition adaptive-type control system for an internal combustion enginemounted on an automotive vehicle having a torque transmission mechanism,a brake pedal and an accelerator pedal, comprising: means forprogramming a plurality of engine control methods with parameters forsaid engine, each of said different engine control methods beingassociated with a combination of one of a plurality of vehicleconditions and one of a plurality of driver's intents, includingbraking, coasting, transient operation, decelerating, cruising andaccelerating; means for discriminating said driver's intent by detectingthe state of said torque transmission mechanism, the angle of said brakepedal and the angle of said accelerator pedal; means for discriminatingsaid vehicle condition by detecting the engine speed and determiningwhether said vehicle is in a rest condition or not; and means forselecting one of said engine control methods in accordance with acombination of the discriminated driver's intent and vehicle condition.25. A condition adaptive-type control method for an internal combustionengine mounted on an automotive vehicle, comprising the steps of:categorizing driver's intents and vehicle conditions into pluralcategories and plural categories, respectively, and preparing pluraltypes of engine control methods, including an acceleration controlmethod, a deceleration control method, an air/fuel ratio control methodand an idle speed control method, which correspond to respectivecombinations of said categories; detecting one of said plural types ofdriver's intents including braking, transition or coasting,deceleration, running and acceleration; detecting said vehicle conditionincluding engine speed to determine whether said vehicle is in a restcondition or a running condition; and selecting one of said plural typesof engine control methods in accordance with said combination ofcategories to which said detected intent and vehicle condition belong.26. A condition adaptive-type control system for an internal combustionengine mounted on an automotive vehicle comprising: means forcategorizing driver's intents and vehicle conditions into pluralcategories, respectively, and for preparing plural types of enginecontrol methods, including an acceleration control method, adeceleration control method, an air/fuel ratio control method and anidle speed control method, which correspond to respective combinationsof said categories; means for detecting one of said plural types ofdriver's intents including braking, transition or coasting,deceleration, running and acceleration; means for detecting said vehiclecondition including engine speed to determine whether said vehicle is ina rest condition or a running condition; and means for selecting one ofsaid plural types of engine control methods in accordance with saidcombination of categories to which said detected intent and vehiclecondition belong.
 27. A condition adaptive-type control method for aninternal combustion engine mounted on an automotive vehicle havingdriver controlled elements, comprising the steps of: detecting adriver's action in controlling said elements; detecting a driver'spreference from at least one switch set by the driver, said one switchbeing a switch for setting a cruise control for said engine; detectingwhether a distance to a forward vehicle is within a predetermineddistance or not; and outputting a control signal for the engine inaccordance with the results of said steps, the outputted control signalbeing one for changing from the cruise control to a tracking control fortracking the forward vehicle with said predetermined distance when it isdetected by said detecting steps that said cruise control switch is setand the distance is within said predetermined distance.
 28. A conditionadaptive-type control method according to claim 27, further comprises astep of detecting a vehicle speed, and a step of determining saidpredetermined distance in accordance with the detected vehicle speed.29. A condition adaptive-type control method for an internal combustionengine mounted on an automotive vehicle having driver controlledelements, comprising: means for detecting a driver's action incontrolling said elements; means for detecting a driver's preferencefrom at least one switch set by the driver, said one switch being aswitch for setting a cruise control for said engine; means for detectingwhether a distance to a forward vehicle is within a predetermineddistance or not; and means for outputting a control signal for theengine in accordance with the detected driver's action, driver'spreference and distance, the outputted control signal being one forchanging from the cruise control to a tracking control for tracking theforward vehicle with said predetermined distance when it is detected bysaid detecting means that said cruise control switch is set and thedistance is within said predetermined distance.
 30. A conditionadaptive-type control system according to claim 29, further comprisesmeans for detecting a vehicle speed, and means for determining saidpredetermined distance in accordance with the detected vehicle speed.31. A condition adaptive-type control method for an internal combustionengine mounted on an automotive vehicle having driver controlledelements, comprising the steps of: categorizing driver's action andvehicle conditions, respectively, into a plurality of categories, andpreparing different engine control methods for different combinations ofsaid categories; detecting said driver's action in controlling saidelements; detecting said vehicle condition from an operational parameterof said vehicle; selecting one of said engine control methods inaccordance with a combination of the categories to which said detecteddriver's action and vehicle condition belong; and detecting a driver'spreference from at least one switch set by the driver, wherein saidcategorizing step includes a step of categorizing said driver's action,said vehicle conditions and said driver's preference respectively, intoa plurality of categories, and a step of preparing different enginecontrol methods for different combinations of said categories, and saidselecting step includes a step of selecting one of said engine controlmethods in accordance with a combination of the categories to which saiddetected driver's action, vehicle condition and driver's preferencebelong.
 32. A condition adaptive-type control system for in internalcombustion engine mounted on an automotive vehicle having drivercontrolled elements comprising: means for categorizing driver's actionand vehicle conditions, respectively, into a plurality of categories,and for preparing different engine control methods for differentcombinations of said categories; means for detecting said driver'saction in controlling said elements; means for detecting vehicleconditions from at least one operational parameter of said vehicle; andmeans for selecting one of said engine control methods in accordancewith a combination of the categories to which said detected driver'saction and vehicle condition belong.
 33. A condition adaptive-typecontrol system according to claim 31, further comprising means fordetecting a driver's preference from at least one switch set by thedriver, wherein said categorizing means includes means for categorizingsaid driver's action, said vehicle conditions and said driver'spreference respectively, into a plurality of categories, and forpreparing different engine control methods for different combinations ofsaid categories, and said selecting step includes a step of selectingone of said engine control methods in accordance with a combination ofthe categories to which said detected driver's action, vehicle conditionand driver's preference belong.
 34. A condition adaptive-type controlmethod according to claim 36, further comprising a step of detecting adriver's preference from switches set by the driver, wherein saidselecting step includes a step of selecting one of said engine controlmethods in accordance with said detected driver's action, vehiclecondition and driver's preference.
 35. A condition adaptive-type controlmethod according to claim 34, wherein the driver's preference detectedfrom said switches is one of sporty, luxury and economy modes ofdriving.
 36. A condition adaptive-type control method for an internalcombustion engine mounted on an automotive vehicle having differentengine control methods and driver controlled elements, comprising thesteps of: detecting a driver's action in controlling said elements;detecting a vehicle condition from an operational parameter of saidvehicle; and selecting one of said engine control methods in accordancewith combination of said detected driver's action and vehicle condition;wherein said engine control methods include an acceleration controlmethod, a deceleration control method, a fuel cut-off control method, anair-fuel ratio control method and an idle speed control method; andwherein said engine control methods are composed of the combinations oftorque servo, speed servo and tracking servo systems.
 37. A conditionadaptive-type control method for an internal combustion engine mountedon an automotive vehicle having different engine control methods anddriver controlled elements, comprising the steps of: detecting adriver's action in controlling said elements; detecting a vehiclecondition from an operational parameter of said vehicle; selecting oneof said engine control methods in accordance with combination of saiddetected driver's action and vehicle condition; and detecting a driver'spreference from switches set by the driver, wherein said selecting stepincludes a step of selecting one of said engine control methods inaccordance with said detected driver's action, vehicle condition anddriver's preference; wherein said engine control methods include anacceleration control method, a deceleration control method, a fuelcut-off control method, an air-fuel ratio control method and an idlespeed control method, and the driver's preference detected from saidswitches is one of sporty, luxury and economy modes of driving.
 38. Acondition adaptive-type control method according to claim 37, whereinsaid engine control methods are composed of the combinations of torqueservo, speed servo and tracking servo systems selected in accordancewith said detected driver's preference.
 39. A condition adaptive-typecontrol system for an internal combustion engine mounted on anautomotive vehicle having different engine control methods and drivercontrolled elements comprising: means for detecting a driver's action incontrolling said elements; means for detecting a vehicle condition froman operational parameter of said vehicle; and means for selecting one ofsaid engine control methods in accordance with a combination of saiddetected driver's action and vehicle condition; and means for detectinga driver's preference from switches set by the driver; wherein saidselecting means includes means for selecting one of said engine controlmethods in accordance with said detected driver's action, vehiclecondition and driver's preference.
 40. A condition adaptive-type controlsystem according to claim 39, wherein said engine control methodsinclude an acceleration control method, a deceleration control method, afuel cut-off control method, an air-fuel ratio control method and anidle speed control method, and the driver's preference detected fromsaid switches is one of sporty, luxury and economy modes of driving. 41.A condition adaptive-type control system for an internal combustionengine mounted on an automotive vehicle having different engine controlmethods and driver controlled elements comprising: means for detecting adriver's action in controlling said elements; means for detecting avehicle condition from an operational parameter of said vehicle; andmeans for selecting one of said engine control methods in accordancewith a combination of said detected driver's action and vehiclecondition; wherein said engine control methods include an accelerationcontrol method, a deceleration control method, a fuel cut-off controlmethod, an air-fuel ratio control method and an idle speed controlmethod; and wherein said engine control methods are composed of thecombinations of torque servo, speed servo and tracking servo systems.42. A condition adaptive-type control system for an internal combustionengine mounted on an automotive vehicle having different engine controlmethods and driver controlled elements comprising: means for detecting adriver's action in controlling said elements; means for detecting avehicle condition from an operational parameter of said vehicle; meansfor selecting one of said engine control methods in accordance with acombination of said detected driver's action and vehicle condition; andmeans for detecting a driver's preference from switches set by thedriver, wherein said selecting means includes means for selecting one ofsaid engine control methods in accordance with said detected driver'saction, vehicle condition and driver's preference; wherein said enginecontrol methods include an acceleration control method, a decelerationcontrol method, a fuel cut-off control method, an air-fuel ratio controlmethod and an idle speed control method.
 43. A condition adaptive-typecontrol system according to claim 42, wherein the driver's preferencedetected from said switches is one of sporty, luxury and economy modesof driving.
 44. A condition adaptive-type control method for an internalcombustion engine mounted on an automotive vehicle having differentengine control methods and driver controlled elements comprising: meansfor detecting a driver's action in controlling said elements; means fordetecting a vehicle condition from an operational parameter of saidvehicle; means for selecting one of said engine control methods inaccordance with a combination of said detected driver's action andvehicle condition; and means for detecting a driver's preference fromswitches set by the driver, wherein said selecting means includes meansfor selecting one of said engine control methods in accordance with saiddetected driver's action, vehicle condition and driver's preference;wherein said engine control methods include an acceleration controlmethod, a deceleration control method, a fuel cut-off control method, anair-fuel ratio control method and an idle speed control method, and thedriver's preference detected from said switches is one of sporty, luxuryand economy modes of driving; and wherein said engine control methodsare composed of the combinations of torque servo, speed servo andtracking servo systems selected in accordance with said detecteddriver's preference.
 45. A condition adaptive-type control method for aninternal combustion engine mounted on an automotive vehicle havingtorque servo, speed servo and tracking servo systems and reference setupunits, comprising the steps of: setting up a first reference signal ofan engine torque, measuring the actual torque of said engine, comparingsaid first reference signal with said measured torque so as to produce afirst error signal indicative of a difference between said referencesignal and said measured torque, and producing a torque control signalin accordance with said first error signal; setting up a secondreference signal of a vehicle speed, measuring an actual vehicle speedof said vehicle, comparing said second reference signal with saidmeasured vehicle speed so as to produce a second error signal indicativeof a difference between said second reference signal and said measuredvehicle speed, and producing a speed control signal corresponding tosaid first error signal in accordance with said second error signal;setting up a third reference signal of a distance to a forward vehicle,measuring the actual distance to a forward vehicle, comparing said thirdreference signal with said measured distance so as to produce a thirderror signal indicative of a difference between said third referencesignal and said measured distance, and producing a tracking controlsignal corresponding to said second error signal in accordance with saidthird error signal; detecting an output of a running control selectorswitch for selecting one of said servo systems; determining one servosystem among said tracking servo system, speed servo system and saidtorque servo system in accordance with said output of said runningcontrol selector switch and said first, second and third referencesignals so as to control said selected servo system to provide saidreference signals to said reference setup units of the selected servosystem; and controlling fuel injection and/or ignition timing of saidengine in response to said torque control signal from said torque servosystem.
 46. A condition adaptive-type control method for an internalcombustion engine mounted on an automotive vehicle, having drivercontrolled elements, torque servo, speed servo and tracking servosystems, reference setup units, a condition discriminating unit, anddifferent engine control methods comprising the steps of: setting up afirst reference signal of an engine torque, measuring the actual torqueof said engine, comparing said first reference signal with said measuredtorque so as to produce a first error signal indicative of a differencebetween said reference signal and said measured torque, and producing atorque control signal in accordance with said first error signal;setting up a second reference signal of a vehicle speed, measuring anactual vehicle speed of said vehicle, comparing said second referencesignal with said measured vehicle speed so as to produce a second errorsignal indicative of a difference between said second reference signaland said measured vehicle speed, and producing a speed control signalcorresponding to said first error signal in accordance with said seconderror signal; setting up a third reference signal of a distance to aforward vehicle, measuring the actual distance to a forward vehicle,comparing said third reference signal with said measured distance so asto produce a third error signal indicative of a difference between saidthird reference signal and said measured distance, and producing atracking control signal corresponding to said second error signal inaccordance with said third error signal; categorizing driver's actionand vehicle conditions, respectively, into a plurality of categories,and preparing different engine control methods for differentcombinations of said categories; detecting said driver's action incontrolling said elements; detecting said vehicle condition from anoperational parameter of said vehicle; and detecting an output of arunning control selector switch for selecting one of said servo systems;determining one engine control method among different engine controlmethods previously stored in said condition discriminating unit inaccordance with a combination of said categories of said driver's actionand said vehicle condition, and determining one servo system among saidtracking servo system, speed servo system and said torque servo systemin accordance with said output of said running control selector switchand said first, second and third reference signals so as to control saidselected servo system to operate in accordance with said determinedengine control method and to provide said reference signals to saidreference setup units of the selected servo system; and controlling fuelinjection and/or ignition timing of said engine in response to saidtorque control signal from said torque servo system.
 47. A conditionadaptive-type control method according to claim 46, wherein saiddifferent engine control methods include an acceleration control method,a deceleration control method, a fuel cut-off method, an air/fuel ratiocontrol method and an idle control method, said idle control methodbeing operated with said speed servo system and the other four enginecontrol methods being operated with said torque servo system.
 48. Avehicle comprising: first subsystem which includes means for detecting adriver's behavior, means for detecting a vehicle condition and means fordetecting an environmental condition and for generating a signal inaccordance with the output of said detecting means; and a secondsubsystem which controls the vehicle in accordance with said signal;wherein said environmental condition is given by a signal of a distancebetween the vehicle and an obstacle and/or a preceding vehicle detectedby a distance sensor provided for the vehicle; wherein said firstsubsystem includes driver's preference selector switches and generatesthe signal for said second subsystem in accordance with a signal givenby one of said selector switches.
 49. An adaptive control system for anautomotive vehicle having driver controlled elements comprising: firstsubsystem which includes means for detecting a driver's behavior incontrolling said elements, means for detecting a vehicle condition froman operational parameter of said vehicle and means for detecting anenvironmental condition, generates a reference signal in accordance withthe output of said detecting means; and second subsystem which includesa feedback control, controls the vehicle in accordance with saidreference signal a feedback signal corresponding to said control;wherein said environmental condition is given by a signal of a distancebetween the vehicle and an obstacle and/or a preceding vehicle detectedby a distance sensor provided for the vehicle; wherein said firstsubsystem includes driver's preference selector switches and generatesthe signal for said second subsystem in accordance with a signal givenby one of said selector switches.